By David Coddington
An asphalt shingle begins in an oil field in Kuwait. Consider the resources it takes to supply the consumer with this building material: The energy behind the drill and the fuel to run it. The crew and all the money, food, and peripherals they need to draw the oil from the ground. The energy and infrastructure required to deliver the crude oil to the tanker ships that deliver it across the oceans to a refinery in Houston. The energy to refine gas, diesel, and other petroleum products from the crude oil. The energy to convert the sludge at the bottom of the barrel into asphalt. The fuel to transport the asphalt to various users, such as road pavers and shingle factories. The energy to manufacture the asphalt shingle. The fuel for CO2-burning vehicles to deliver the shingle to roofing material distribution centers throughout the Midwest. The fuel to deliver the shingle to a building or house. The crew and the energy behind the roofing equipment to install the asphalt shingle on the rooftop, where it will live until it is removed and transported to a landfill.
This is the story that is most riveting to me—the story of embodied energy, or the sum total of energy required, from raw material extraction to deconstruction or decomposition. I’d also like to tell you mine.
In my mid-twenties, after a friend introduced me to a journeyman roofer, I became a trash hauler, shoveling tear-off cedar shingles into the back of a pickup truck. Over the course of my roofing career, from trash hauler to crew manager to owner of 3R Roofing, I have made many runs to the landfill and have seen thousands of tons of roofing material removed, hauled, and dumped.
Not until the passage of Colorado Amendment 37 in 2004 and the institutionalization and production of solar-powered renewable energy did it occur to me that resource conservation and energy efficiency had to be the biggest part of my company’s mission. Power partnering with PV solar installers and jumping on the bandwagon of the renewable energy movement was pretty heady stuff, but I had to ask myself, “What can I do as a roofing contractor to divert materials from the landfill? And what can I do to help my customers reduce their carbon footprint with the roofing material choices they make?”
Here are some important basic issues I discovered:
- Coal-fired utility plants generate about 70 % of Colorado’s electricity. We cool our homes and buildings primarily with coal, and heat our indoor air and water primarily with natural gas. We Coloradans use about 10% more energy, and therefore more of our money, heating our homes than cooling them. Heat gain and heat loss can be significantly affected by attic ventilation and insulation and roofing choices.
- Coal and natural gas are non-renewable resources that produce greenhouse gas (CO2). Solar power and wind power are renewable energy resources that produce no CO2. (Xcel is on course to produce 15–20% of Colorado’s electricity with renewable energy in the next 10 years.) Solid, still-functional rooftops are the site of choice for most photovoltaic (PV) and thermal solar systems.
- Most steel roofing products are made from 35–85% recycled material and are 100% recyclable; and every pound of recycled steel used in manufacturing prevents 1,800 lbs. of CO2. Products with an Energy Star rating provide higher reflectivity and emmisivity, for a cooler house, less energy usage, a cost savings, and less CO2.
- U.S. concrete production, including concrete roofing tiles, causes roughly 8% of all CO2 emissions. Clay tiles have a smaller environmental impact in their manufacturing and can be more durable and attractive. End-use tire rubber, hose, plastics, and carpet are now being used for high-recycled-content roofing products, the installation of which reduces end waste in landfills and curtails the use of high embodied-energy materials. For durability, value, and budget, however, asphalt shingles are preferred for most residential construction. Some asphalt shingles are Energy Star-rated, and lighter colors provide greater cooling benefits than darker ones. Currently, 99% of tear-off asphalt shingles are not recycled in the U.S. (100% go to the landfills in Colorado), though a handful of states use them in their hot mix asphalt for roads. Every ton of tear-off shingles recycled prevents 110 lbs. of CO2.
So, with all this information, what does one do next when considering a new or existing roof? I would ask:
- With all the choices available, what makes the most sense for me? If PV or thermal solar panels is an option, is my roof functional enough to hold the mounting hardware for years to come?
- Is my home or business comfortable enough in the summer? Winter? Would I like to reduce my energy cost considerably? How much CO2 can I offset by my roofing choices?
- What is my best choice for roofing material with regard to energy efficiency, resource conservation, and air quality? What is the embodied-energy impact of my roofing decision?
- If color and appearance are important to me, what choices will reduce heat gain in my home or business? How might I cut the cost of my home/business insurance premium?
Some of the answers are simple and quick; some are not. And roofing choices alone will not address all the considerations. As a green-built roofing contractor, however, I see the reuse of tear-off shingles as imperative to the sustainability of my industry.
To that end, born of 3R Roofing’s vision, RoofCycle has been training roofers, haulers and others to effectively test and deliver clean tear off shingle loads (RAS) to paving contractor collection points for future use in hot mix asphalt for road paving.
RoofCycle is also promoting this process through the building department offices of local municipalities. And, the Colorado Department of Transportation (CDOT) is considering the large scale use of RAS in hybrid mix designs for road paving. This will “pave” the way for a significant amount of processed tear-off shingles—a more promising end to the life of an asphalt shingle.
